Electric-circuit cut-out.



H. M. SGHEIBE.-

ELECTRIC CIRCUIT GUT-OUT.

APPLICATION FILED JUNE 9, 1910.

1 056 220. Patented Mar. 18,1913.

m .nllllllllllllllln 6 W|TNESSES:- INV T R Mil-w BY 7 ATTORNEY UNITEDSTATES PATENT OFFICE.

HAROLD M. SCHEIBE, OF WILKINSBURG, PENNSYLVANIA, ASSIGNOR TO WESTING-HOUSE ELECTRIC AND MANUFACTURING COMPANY, A CORPORATIQN F PENNSYL-VANIA.

To all whom, it may concern:

- Be it known that I, HAROLD M. Sci-mum, a citizen of the United States,and a resident of \Vilkinsburg, in the county of Allegheny and State ofPennsylvania, have invented a new and useful Improvement inElectriclircuit Cut-Outs,o'f which the following IS a specification.

My-invention relates tolautomatic electric circuit-interrupters orcut-outs of the fuse type and it has 'for its object to provide a deviceof'this character in which a fusible member may be heated, both directlyand indirectly, by the' current traversing the electric circuit, for thepurpose of preventing the unnecessary interruption of tl1 -.C1I'Cl11tin' case the current only temporarily exceeds a predetermined amount.

My invention is illustrated in the accompanying drawings, in whichFigure lis' a longitudinal section, and Fig. 2 is a transverse sect-ion,on the hne Q II-II of Fig. 1, of a device constructed in I accordancetherewith. Figs. 3 to 16, inclusive, are detail views of the structureshown in Figs. 1 and 2.

Referring to the drawings, the dev ce comprises a hollow cylinder ortube 1 of msulating material having an insulating plate 2 at one end, atransverse insulating plate 3 near the other end and metal caps 4 and 5which are fitted over the respective ends of the tube.

Aninsulating block or spool 6, con- 5 structed of refractory material,is located within the tube 1, between the transverse plates 2 and 3. Thespool 6, which is-shown in bottom plan in Fig. 9, and in side elevationin Fig. 10, is screw-threaded or grooved I to receive a plurality ofconvolutions of conducting wire 7 which constitutes aheating coil and isconnected in series circuit relation with a fusible strip or wire 8 thatis soldered,,or otherwise electrically connected, 4 at one end, to thecap 4 and is joined, at the other end, to one terminal of the coil 7 Thefusible wire 8 projects through a hole 9 in an end lug-10 of the spool6and is held under tension by means of a spiral spring 11 which iscoiled about a supporting finger 12 that is bent at one end to projectthrough a hole 13 in an end lug 14: which corresponds to the end lug 9..The finger 12 extends through a hole 15 ifixthe transverse plate 3, -5and spiral spring 11 which rests against the ELEGTRIC-CLfRCUIT CUT-OUT.

Specification of Letters Patent. Patented Man 18, 1913 Application filedJune a. 1910. Serial no. 566,106.

outer sin-face of this plate and tends to assume the shape shown in Fig.4, thus maintaining a sufficient tensile strain upon the parts 12, 6 and8 to hold the spool substantially ,in the center of the tube 1. Thefinger 12 is electrically connected to one terminal of the 0011 7 andthe electric circuit is completed from the outer end of thefinger'through a flexible conductor 16 to the cap 5, thecaps 4 and 5constituting the respective terminals of the cut-out. The tube or shell1 is provided with an insulating lining 18, the edges of which arefolded over to space it from the tube and to form an air cell 19 whichcon- StlllltGSfln excellent heat insulator for the device. P

The operation of the device is as follows: The electric heating coil 7and the fuse 8 are so proportioned relative to the normal currenttraversing the circuit that a relatively slight increase in current, ifmaintained for a considerable length oftime, produces sufii-v cient heatin the coil 7 to melt the fusible;

strip 8, but, on the other hand, a'considerable increase in current maytake place for a short' length of time without fusing the wire 8. Whenthe fuse is softened, the pull exerted by the spring 11 ruptures it andso interrupts the electric circuit. .When the circuit is interrupted.the finger 12 assumes such position that its outer end extends through ahole 17 in thecap 5 without destroying or rupturing the flexibleconductor 16. By this means, the condition of the interrupter isexteriorly indicated and it is only, necessary to replace the shortlength of fuse wire in 'order to again put the device into servicecondition.

The cut-out-may' be made of such size-and shape as to correspond to astandard inclosed fuse, so that it may replace a fuse of this characterwithout necessitating any change in the usual stationary contactmembers.

It is evident that the material employed for the heating coil andfusible member and the structural details of the device may be variedwithin the spirit and scope of mylinvention.

I claim as my invention:

' 1. A cut-out for electric cn'cuits comprising an insulating block, aheater element surrounding said block, a fusible wire or strip in seriescircuit relation, and resilient means for holding the fusible wire orstrip under tension and cooperating therewith to suspend the block andthe heater element out of engagement with adjacent bodies.

2. A cut-out for electric circuits comprising a helically groovedinsulating block, a heating coil/located in the grooves of said block, afusible strip in series circuit relation with said coil, and means forholding the fusible strip under tension.

3. A cut-out forelectric circuits comprising a chamber, an insulatingblock, a heat-v ing coil surrounding said block, a fusible strip locatedin said chamber and having its respective ends fastened to said blockand to a wall of said chamber, and means for holding said strip undertension to suspend the heating coil and its block in thechamber,

the current traversing the cut-out beingadapted to influence the fusiblestrip by means of heat generated insaid coil..

4. A cut-out for electric circuits comprising a refractory spool orblock, a heating coil wound thereon, a pair'of conducting membersrespectively connected to the terminals of the heating coil and aspringfor holding the parts under tension, one of said conductingmembers being fusible at relatively low temperatures. t 5.. Acut-outvfor electric clrcuits compris:

ing an inclosing casing having endcaps of conducting material, a spoolof insulating -material, a heating coil wound on the spool,

two conductors mechanically joined to the 'ends of the spool andelectrically connected to the terminals of the heating, coil'and aspring for holding the conductors and the spool under tension, one-'ofsaid conductors being fusible and connected to one conducting cap, andthe other conducting member being yieldingly connected to the oppositecap and responsive to the action of the spring upon the rupture of theother.member.

ing a tube or shell, an insulating lining having outwardly folded endsto space it from the tube or shell, a heating coil and a fusible striplocated therein under tension.

7 A cut-outfor electric circuits comprising a tube or shell, aninsulating lining hav- 6. A cut-out for electric circuits .con1pris-'ing annular projections between it and the,50

inner peripheral wall of the tube or shell, a

heating coll, a fusible strip located therein,

and a spring for holding the parts under tension, one of said conductingmembers being fusible at relatively low temperatures.

